• Question: How do hurricanes happen?

    Asked by victor9 to Austin, Kirsty, Nicola, Nike, Sarah on 21 Jun 2012. This question was also asked by toad9.
    • Photo: Kirsty Ross

      Kirsty Ross answered on 21 Jun 2012:

      A hurricane is an intense, rotating oceanic weather system that possesses maximum sustained winds exceeding 119 km/hr (74 mph). It forms and intensifies over tropical oceanic regions. Hurricanes are generally smaller than storms in mid-latitudes, typically about 500 km (311 miles) in diameter. At the ocean’s surface, the air spirals inward in a counterclockwise direction. This cyclonic circulation becomes weaker with height, eventually turning into clockwise (anticyclonic) outflow near the top of the storm.

      Hurricanes form and intensify over oceanic regions. They require sea-surface temperatures of at least 26°C (80°F) and the influence of the earth’s rotation to initiate a spinning circulation (Coriolis effect).

    • Photo: Nike Dattani

      Nike Dattani answered on 22 Jun 2012:

      If you throw a ball high enough in the air, the Earth will rotate a bit before the ball lands, so it will not land exactly where you threw it. This is called the Coriolis effect. Hurricanes happen due to the Coriolis effect and a build up of high pressure, so it is the rotation of the Earth that’s responsible for hurricanes.